The uv1 Neuroendocrine Cells Provide Mechanosensory Feedback of Vulval Opening.

Neuroendocrine cells react to physical, chemical, and synaptic signals originating from tissues and the nervous system, releasing hormones that regulate various body functions beyond the synapse. Neuroendocrine cells are often embedded in complex tissues making direct tests of their activation mechanisms and signaling effects difficult to study. In the nematode worm , four uterine-vulval (uv1) neuroendocrine cells sit above the vulval canal next to the egg-laying circuit, releasing tyramine and neuropeptides that feedback to inhibit egg laying.

The Sex-Specific VC Neurons Are Mechanically Activated Motor Neurons That Facilitate Serotonin-Induced Egg Laying in .

Successful execution of behavior requires coordinated activity and communication between multiple cell types. Studies using the relatively simple neural circuits of invertebrates have helped to uncover how conserved molecular and cellular signaling events shape animal behavior. To understand the mechanisms underlying neural circuit activity and behavior, we have been studying a simple circuit that drives egg-laying behavior in the nematode worm Here we show that the sex-specific, ventral C (VC) motor neurons are important for vulval muscle contractility and egg laying in response to serotonin.

Identification of Toxicity Effects of CuO Materials on as a Function of Environmental Ionic Composition.

Previous work has shown that spherical CuO nanomaterials show negative effects on cell and animal physiology. The biological effects of CuO materials, which posess unique chemical features compared to CuO nanomaterials and can be synthesized in a similarly large variety of shapes and sizes, are comparatively less studied. Here, we synthesized truncated octahedral CuO particles and characterized their structure, stability, and physiological effects in the nematode worm animal model, .

Activity of the egg-laying behavior circuit is controlled by competing activation and feedback inhibition.

Like many behaviors, egg laying alternates between inactive and active states. To understand how the underlying neural circuit turns the behavior on and off, we optically recorded circuit activity in behaving animals while manipulating circuit function using mutations, optogenetics, and drugs. In the active state, the circuit shows rhythmic activity phased with the body bends of locomotion.

The YsrS Paralog DygS Has the Capacity To Activate Expression of the Yersinia enterocolitica Ysa Type III Secretion System.

Unlabelled: The Yersinia enterocolitica Ysa type III secretion system (T3SS) is associated with intracellular survival, and, like other characterized T3SSs, it is tightly controlled. Expression of the ysa genes is only detected following growth at low temperatures (26°C) and in high concentrations of sodium chloride (290 mM) in the medium. The YsrSTR phosphorelay (PR) system is required for ysa expression and likely responds to NaCl.